Water-tube boiler



A. COTTON.

WATER TUBE BOILER. I I APPLICATION FILED MAY I0. 1920 1 43x495 Patented Dec. 5, 1922.

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lf/VEA/TOR 6 FEED (0 T TOM BY I H TTORNEYS "A'. COT'TON WATER TUBE BOILER. APPLICATION FILED MAY 10, I920.

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Patented Dc. 5, 1922.

5 SHEETS-SHEET 2.

INVENTOR F250 Co 7 row.

A 77' ORNE A. COTTON.

. WATER TUBE BOILER. APPLICATION FILED my 10. I920.

Patented. Dec. 5 22.

5 SHEETS-SHE /j I E l M s 3 flA FEED C0 TTOM f A. comm WATER TUBE'BOILiER. APPLICATION BLED MAY 10. 1920.

Patented Dec. 5, 922.

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Patented Use. 5, i922.

STATS Aren't OFFICE.

ALFRED COTTON, OF ST. LOUIS, MISSOURI, ASSIGNOR TO T I EINE BOILER COMPANY, OF ST. LOUIS,.MISSOURI, A CORPORATION OF MISSOURI.

WATER-TUBE BOILER.

Application filed May 10,

To all whom it may concern:

Be it known that I, ALFRED COTTON, a citizen of the United States, residing at St. Louis, Missouri, have invented a certain new and useful Improvement in WVater- Tube Boilers, of which the following is a full, clear, and exact description, such as will enable .others skilled in the art to which it appertains to make and use the same.

This invention relates to water tube boilers of the cross drum, upright tube type, and particularly, boilers of the kind described in my pending application Serial No. 373,250, filed April 12, 1920, wherein a shield or partition is arranged at the rear side of the combustion chamber in such a manner that the long flame gases from the front of the fire will rise upwardly through the combustion chamber before crossing over the front tubes of the boiler, and the short flame gases from the back of the fire will escape from the combustion chamber under the lower edge of said shield or partition and then flow upwardly among water tubes arranged at the rear side of said shield.

One object of my present invention is to increase the efiiciency of boilers of the particular kind just referred to by increasing the proportion of work done in the tubes or bank of tubes arranged immediately behind the shield or partition which divides or separates the long and short flame gases rising from the fire.

Another object of my invention is to improve the circulation of boilers of the Stirling type and the Ladd type and also of the four bank type, wherein two banks of tubes are employed for conducting the water upwardly from the mud drum to separate and distinct elevated cross drums.

And still another object is to provide a boiler in which the last pass may be either upward or downward without increasing the number of passes, without lengthening the path of the gases, and consequently, increasing the draft resistance, without corresponding advantage in heat transfer, and without complicated baffling. Other objects and desirable features of my invention will be hereinafter pointed out.

To this end I have devised a boiler, which, in addition to being equipped with a shield or partition arranged at the rear 1920. Serial No. 380,284.

side of the combustion chamber for separating the long flame gases rising from the front of the fire from the short flame gases rising from the b ack of the fire, is so constructed that said long and short flame gases will flow downwardly and upwardly, respectively, approximately half the length of the tubes directly behind the shield before said bodies of gases converge. By constructing the boiler in this manner I cause both bodies of gases, namely, the long flame gases and the short flame gases, to give up about the same amount of heat and leave the tube bank immediately behind the shield at about the same temperature.

a Figure 1 of the drawings is a vertical longitudinal sectional View of a Stirling type boiler constructed in accordance with my invention.

Figure 2 is a similar view, showing how the baiiles can be arranged when it is desired to have the last pass a downward pass.

Figure 3 is a vertical, longitudinal sectional view of a four bank boiler constructed in accordance with my invention.

Figure 4 is a vertical, longitudinal sectional view of a boiler of the kind shown in figure 1, equipped with a superheater; an

Figure 5 illustrates my invention applied to a boiler of the Ladd type.

When a greater proportion of heat is transferred from the gases to the water in the convected heat bank of a fourbank boiler or in the front bank of a Stirling or Ladd boiler, the temperature of the gases leaving such banks is necessarily lower. It is obvious that when the temperature of the gases leaving such banks is lower,the temperature of the gases escaping through the gas outlet of the boiler will also be lower; and the lower the temperature of the gases leaving the boiler, the greater is the efiiciency of the boiler. It is understood that other conditions are unchanged while making the above comparisons.

When a greater proportion of heat is transferred in these front banks, a correspondingly less proportion is transferred in. the rear tube bank of the boiler, and there is less tendency to reverse the flow in the downeomer bank, so that the circulation is rendered more rapid.

In other words, with a lower temperature of the gases entering the downcomer bank of the boiler, less heat is transferred, and less steam is generated in the downcomer bank, with less of the pumping action which impedes downward flow.

My present invention, briefly described, consists of a boiler either of the Stirling type or of the Ladd type, as shown in Figures l and 5 respectively, or of the four bank type, as shown in Figure 8, provided with a shield or partition A arranged at the rear side of the combustion chamber in such a manner that the long flame gases or hydrocarbon gases rising from the front of the fire, indicated by the reference character 03, will flow upwardly through the combustion chamber of the boiler before crossing over the front tubes of the boiler, and the short flame gases from the back of the tire, indicated by the reference character 3 will escape from the combustion chamber under the lower edge of said shield A, and means for causing said gases to flow in opposite directions part way the length of the tubes immediately behind the said shield and then converge and flow among the other tube banks to the gas outlet at the back of the boiler. In the boiler shown in Figure 1 a battle B, which is arranged at the rear side of the first tube bank 1 with its upper end in contact with the front steam-and-water drum 2 of the boiler and its lower end in contact with the mud drum 3, is provided intermediate its ends with an opening 4. When the boiler is in operation the long and short flame gases from the front and from the back of the fire escape from the combustion chamber of the boiler over the upper edge and under the lower edge, respectively, of the shield A and then flow downwardly and upwardly longitudinally of the front tube bank 1 to the the opening 4 in the baflleB. -Consequently, each of said bodies of gases give up about the same amount of heat and leave the front bank 1 at about the same temperature. In other words, the temperature drop of the long flame gases, in traveling downwardly over the upper half of the bank 1, will be the same as that of the short flamegases'traveling upwardly over the lower half of the bank 1. Accordingly, a boiler of the construction above described is more eflicient than a boiler of the kind wherein only the short flame gases flow upwardly among the tubes of the tube bank immediately behind. the shield or partition A and the long flame gases merely flow rearwardly over the upper edge of said shield and then mingle with the upwardly flowing short flame gases, due to the fact that the proportion of work done in the tube bank immediately behind the shield or partition A. is materially increased. To state it in another way, when a boiler equipped with a shield or partition for splitting up the gases rising from the front and from the back of the tire, is so constructed that the two bodies of gases mix at the upper end of the tube bank immediately behind the shield, the resulting temperature is the mean of the temperatures of the two bodies of gases, As the temperature drop of the short flame gases which have traveled the entire length of said tube bank is very much less than twice the temperature drop whenonly half the length of said tube bank is traveled, the mean temperature of the gases leaving this tube bank is much higherthan when each body of gases travels over half the length of the tube bank, as in the boiler herein illustrated.

Another desirable feature of my improved boiler is that the gas velocity is relatively high, due to the comparatively small crosssectional area of the passageway through which the long flame gases travel after pass ing overthe upper edge of the shield A.

This higher velocity is advantageous, in that it increases the heat transfer rate in the tube bank 1 immediately behind the shield or partition A.

As the gases leave the tube bank 1 at mid height, or substantially so, it is immaterial whether said gases enter the next tube bank at the top'or the bottom of said bank. Consequently, it is equally easy to make the last pass of the boiler an up pass or a down pass. Therefore, in Figure 2 I have illustrated a boiler which is substantially the same as the boiler illustrated in Figure 1, except that the battles at the front and at the rear of the second tube bank 5 are arranged diflerently. In the boiler shown in Figure 1 the second baffle C extends upwardly from the mud drum 3 and terminates below the mid dle steam-antLwater drum 6 and the third battle D extends downwardly from the middle drum 6 at the rear side of the second tube bank 5 and terminates above the mud drum, thus causing the gases to travel upwardly among the tubes of the last bank 7 to a gas outlet 8 at the upper end of the boiler. In the boiler shown in Figure 2 the second and third baffles C and D are oppositely arl ranged so that the final pass is a down pass to a gas outlet .8 at the lower end of the boiler. I

in Figure 3 I have illustrated my invention embodied in a boiler of the four bank type, wherein two banks of tubes 1 and 5 are provided for conducting the water upwardly from the mud drum 3 to the front drum 2 and the middle drum 6, thus causing part of the water'to be supplied directly to the front drum and the remainder to be supplied directly to the middle drum. A bank of downcomer tubes 5 connects the middle drum 6 with the mud drum so as to conduct the water which enters both of the drums 2 merges and 6 back to the mud drum 8, the front and middle drums being connected with each other by steam and water circulators. The shield or partition A which is arranged at the rear side of the radiant heat bank 1 divides or separates the long flame gases from the short flame gases and the front baflle B which is arranged at the rear side of the convected heat bank 5 is provided approximately midway its height with. an open ing a through which the long and short flame gases escape after traveling downwardly and upwardly among the tubes of the conveoted I heat bank.

In the boiler shown in Figure 4, which is of substantially the same construction as the boiler shown in Figure 1, a superheater E is arranged in a chamber behind the first ba'lfle B, the mixed gases which escape through the opening 4 in said baffle flowing through said chamber and thus heating the superheater E.

In Figure 5 I have illustrated my invention embodied in a Ladd boiler equipped with a shield or partition A for separating the long flame gases from the short flame gases, and a baflie B arranged behind said shield and provided at a point intermediate its upper and lower ends with an opening 4: through which the long and short flame gases escape from the tube bank 1 immediately behind the shield A after flowing downwardly and upwardly among the tubes of said bank.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. A, water tube boiler of the upright tube type provided. with a partition arranged at the rear side of the combustion chamber in such a manner that the long and short flame gases rising from the front and from the back of the fire will be separated and dirooted in different paths, and means for causing said bodies of gases to contact with the tubes of the bank immediately behind said partition and leave said bank adjacent the middle of the height of said bank at substantially the same temperature.

2. A water tube boiler of the upright tube type provided with means for separating he gases rising from the front and from the rear of the fire into two bodies, and means for causing said bodies of gases to flow in. opposite directions over a bank of tubes arranged adjacent the front of the boiler and give up about the same amount of heat to said tube bank.

3. A water tube boiler of the upright tube type, comprising a bank of tubes, a partition arranged in front of said tube bank for separating the long flame gases rising from the front of the fire from the short flame gases rising from the back of the fire, and means for causingsaid bodies of gases to circulate over the tubes of said bank in opposite directions so that the temperature drop of the long flame gases will be substantially the same as the temperature drop of the short flame gases.

4:. A boiler of the uprighttube type provided with a partition arranged at the rear side of the combustion chamber in such a manner that it will separate the long flame gases rising from the front of the fire from the short flame gases rising from the back of the fire and cause said bodies of gases to follow different paths, and means for causing said bodies of gases to flow in opposite directions approximately half the length of the tube bank immediately behind said partition and then converge and leave said bank.

5. A water tube boiler of the upright tube type provided with a shield arranged so that the long flame gases and the short flame gases rising from the front and from the back of the fire will be separated and directed in different paths, and means for causing the long flame gases to flow downwardly among the tubes directly behind said shield approximately half the length of said tubes'and the short flame gases to flow upwardly among said tubes and then mix with said long-flame gases.

6. A boiler of the upright tube type provided with a shield arranged so that it will separate the long and short flame gases rising from the front and from the back of the fire and cause said bodies of gases to follow different paths, a bank of tubes arranged behind said shield, and a baffle arranged behind said tube bank and provided intermediate its upper and lower ends with an opening through which the gases escape after circulating over the tubes of said bank.

7. A boiler of the upright tube type provided with a bank of tubes, a mud drum communicating with the lower end of said tube bank, an elevated transverse drum communicating with the upper end of said tube bank, a battle arranged at the rear of said tube bank and provided at substantially its center with a gas passageway or opening, and a partition arranged at the front of said tube bank for separating the long flame gases rising from the front of the fire from the short flame gases rising from the back of the fire.

8. A boiler of the upright tube type provided with a partition arranged at the rear side of the combustion chamber for causing the gases rising from the front and from the back of the fire to separate and follow different paths, water tubes behind said partition located outside of the combustion chamber, means for causing said bodies of gases to flow longitudinally in opposite di rections among the tubes directly behind said partition and then commingle, and a superheater arranged so that it will be heated by the mixed gases which escape from the tube bank immediately behind said s iield.

9. A Water tube boiler provided with a bank of upright Water tubes, a partition arranged in front of said bank for separating the leng flame gases rising from the front of the fire and from the short flame gases rising from the back of the fire, and a superheater chamber arrangedatthe rear side of said tube bank and provided with an inlet so disposed that the long and short fiaine gases will flew in opposite directions among the tubes of said bank, commingle and then enter said superheater chamber at approximately the same temperature.

ALFRED COTTON. 

